首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3333篇
  免费   446篇
  国内免费   60篇
耳鼻咽喉   24篇
儿科学   90篇
妇产科学   63篇
基础医学   338篇
口腔科学   144篇
临床医学   375篇
内科学   661篇
皮肤病学   77篇
神经病学   180篇
特种医学   85篇
外科学   466篇
综合类   293篇
现状与发展   1篇
预防医学   313篇
眼科学   60篇
药学   359篇
  8篇
中国医学   107篇
肿瘤学   195篇
  2024年   14篇
  2023年   90篇
  2022年   140篇
  2021年   238篇
  2020年   176篇
  2019年   168篇
  2018年   167篇
  2017年   147篇
  2016年   99篇
  2015年   133篇
  2014年   172篇
  2013年   159篇
  2012年   203篇
  2011年   162篇
  2010年   110篇
  2009年   90篇
  2008年   116篇
  2007年   129篇
  2006年   147篇
  2005年   116篇
  2004年   91篇
  2003年   108篇
  2002年   83篇
  2001年   59篇
  2000年   82篇
  1999年   74篇
  1998年   25篇
  1997年   33篇
  1996年   30篇
  1995年   17篇
  1994年   19篇
  1993年   17篇
  1992年   38篇
  1991年   33篇
  1990年   53篇
  1989年   33篇
  1988年   20篇
  1987年   25篇
  1986年   21篇
  1985年   10篇
  1984年   24篇
  1983年   19篇
  1982年   9篇
  1981年   11篇
  1979年   17篇
  1978年   11篇
  1975年   9篇
  1974年   13篇
  1973年   10篇
  1971年   10篇
排序方式: 共有3839条查询结果,搜索用时 43 毫秒
1.
目的 检测蒜氨酸最低抑菌浓度(MIC)与最低杀菌浓度(MBC),探讨蒜氨酸体内外抗菌机制。方法 体外微量稀释法检测蒜氨酸MIC和MBC,荧光显微镜观察菌体表面蒜氨酸,探讨蒜氨酸抗菌机制。体内蒜氨酸和青霉素分别治疗金葡菌感染家兔脓肿,检测脓汁标本中细菌存活情况,探讨体内蒜氨酸抗菌作用。结果 蒜氨酸对大肠杆菌、伤寒杆菌、金黄色葡萄球菌、白色葡萄球菌的MIC分别为3.047 μg·mL-1、6.094 μg·mL-1、0.386 μg·mL-1、0.386 μg·mL-1,蒜氨酸体外无杀菌活性。浓汁标本:死菌率蒜氨酸治疗组显著高于阴性对照组(P < 0.01),与青霉素治疗组无明显差异(P > 0.05);活菌率蒜氨酸治疗组显著低于阴性对照组(P < 0.01),与青霉素治疗组无明显差异(P > 0.05)。结论 蒜氨酸与菌体蛋白、细菌酶蛋白结合阻断细菌与环境物质交换,抑制细菌生命活动,具有较强的抑菌作用,无杀菌活性;蒜氨酸体内代谢成大蒜素,具有较强杀菌作用。  相似文献   
2.
综述护士个人-组织契合度的概念、评估工具以及现状,通过分析影响护士个人-组织契合度的因素,明确提高护士个人-组织契合度的策略,以期为护理管理者改善护士工作环境,构建良好稳固的护理队伍提供参考.  相似文献   
3.
目的:探讨lncRNA RP11-86H7.1在川崎病(KD)患者血清中的表达及其与临床病理特征及预后的关系。方法:筛选KD特异相关的循环lncRNA,分KD治疗前患儿组、KD治疗后患儿组、普通发热患儿组及健康儿童组,采用qPCR检测各组血清lncRNA RP11-86H7.1相对表达。分析血清lncRNA RP11-86H7.1相对表达与KD临床病理特征间关系;绘制ROC曲线,分析血清lncRNA RP11-86H7.1表达水平对KD的诊断效能。结果:KD急性患儿组血清lncRNA RP11-86H7.1相对表达量高于各对照组(P<0.05);年龄和性别比例与低表达组比较差异无统计学意义(P>0.05);qPCR发现lncRNA RP11-86H7.1在KD急性期患儿血清中表达水平明显高于KD恢复期、健康儿童及发热儿童组,差异均有统计学意义(P<0.05)。结论:血清lncRNA RP11-86H7.1在KD患者中表达上调,其可作为KD早期诊断和评估预后的潜在的生物标志物。  相似文献   
4.
The relationship between bladder cancer and occupational exposure to asbestos was investigated between 1978 and 1982 at La Paz Hospital in Madrid in a case-control study conducted among 353 male patients and 53 women with a diagnosis of urothelium carcinoma, and among an equal number of controls matched in age (decade of life), sex and date of admission to the hospital. The results showed that bladder cancer is associated with occupational exposure to asbestos.  相似文献   
5.
An association between the occurrence of antibodies to simian vacuolating virus 40 and bladder cancer in male smokers was found in a case-control study conducted in 200 male patients with bladder cancer and 400 control men. The risk of bladder cancer increases with the years of cigarette smoking.  相似文献   
6.
We have utilized the rat hepatoma (HTC) cell sorting variant CR4 to examine the glucocorticoid-regulated pathways that localize mouse mammary tumor virus glycoproteins to the cell surface. The defective sorting of cell surface mouse mammary tumor virus glycoproteins in CR4 cells was complemented after fusion with either normal rat hepatocytes or uninfected HTC cells. Indirect immunofluorescence of transient heterokaryons revealed that the regulated localization of mouse mammary tumor virus glycoproteins was dependent upon glucocorticoid treatment and required de novo RNA and protein synthesis. Thus, a glucocorticoid-regulated trafficking activity, unrelated to mouse mammary tumor virus sequences, which is induced in both adult rat liver and cultured hepatoma cells, can act in trans to mediate an intracellular sorting pathway for membrane glycoproteins.  相似文献   
7.
Objective:  Prevalence of textile dye contact dermatitis (TD‐CD) are lacking in many countries. Our aim is to know the frequency of TD‐CD in three different areas of Spain.
Methods:  100 patients were tested with Spanish standard series and the five most frequent TD in each city. D. Orange 1, D. Orange 3, D. Blue 35, D. Blue 106, D. Blue 124 were included in Murcia and Seville, and the three last and D. Red 1, D. Red 17 in Santiago.
Results:  23/300 (15 women and 8 men) were positives to one or more TD. D. Blue 124 was the most frequent allergen (18/300), followed by D. Blue 106 (17/300). D. Red 1, D. Red 17 and D. Orange 1 were positives in 2/200. D. Orange 3 and D. Blue 35 were positives in 1/200. Eczema was located on hands in 13 cases. Clinical picture was variable. Origin of sensitization was clothing and occupational. Relevance was obtained in 20/23 cases.
Conclusions:  The study confirm an high frequency of disperse dye allergy in Spain with a very different prevalence in the three areas: Seville 14%, Murcia 5% and Santiago 4%, that are probably due to social and cultural factors. We recommend the inclusion of D. Blue 106, D. Blue 124, D. Blue 35, D. Red 1, D. Red 17, D. Orange 1 and D. Orange 3 in standard series in order to detect sensitivity to textile colours that is most frequent than previously suspected.  相似文献   
8.
Summary Thirty adult patients presenting with medulloblastoma between 1974 and 1991 were studied and treated at Puerta de Hierro Clinic. After diagnosis, all patients were treated by surgery followed by radiotherapy and eight of them received adjuvant chemotherapy. We have studied the influence of some factors such as age, sex, location of tumour in the cerebellum, amount of surgical resection and histological variants on survival and recurrence of the disease. Only the histological type has a statistically significant influence on survival and recurrence: we have found that patients presenting classic medulloblastoma have a long survival and a long relapse-free interval.  相似文献   
9.
This study hypothesized that family role (marital and parental status) would moderate the effect of disaster exposure on the mental health of victims. The study included St. Louis residents exposed to floods and dioxin, as well as Puerto Rican respondents exposed to floods and mudslides. In St. Louis, worst outcomes were found for single and married parents exposed to disaster, substantially exceeding the symptomatology of all unexposed respondents except non-victim single parents. In Puerto Rico, victims without families had higher levels of alcohol abuse symptoms than did any other subgroup. Perceived emotional support was found to be an important moderator of disaster's effect on psychiatric distress in this site, generally overriding the effect of family role. Single parents in both sites who were exposed to disaster had substantially reduced levels of emotional support available to them, as compared to unexposed single parents, suggesting that single parents are at particularly high risk for losing access to emotional support following a disaster. This study suggests that both single and married parents constitute important high-risk victim groups. The findings also suggest that those perceiving they lack adequate emotional support, regardless of family role, may be in special need of services.  相似文献   
10.
cDNA clones of potato virus X (PVXcp strain), potato virus Y (PVYo strain), potato leaf roll virus (PLRV) and potato spindle tuber viroid (PSTV) were used separately or combined for the detection of the corresponding RNAs in extracts of infected plants. A general method for the rapid preparation of RNA extracts without use of organic solvents (i.e. phenol) was developed for this purpose. Plant extracts from a range of field, artificially inoculated germplasm genotypes, micro-propagated and protoplast samples, as well as vector insect extracts, were dot-blotted onto nylon or nitrocellulose membranes, subjected to sandwich nucleic acid hybridization with non-labelled specific single-stranded DNA probes followed by a biotin-labelled second step hybridization probe. Each probe was virus-specific but not strain-specific. Healthy or non-related plant extracts developed very faint or no signals. Sensitivity was tested by slot-blot hybridization. Detection levels were between 1.5 to 6 pg of viral nucleic acids and between 20 to 50 times more sensitive than standard double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). The assay developed was tested with material that was prepared for processing in the field (combination of fresh sap with extraction solution) and tested under simple laboratory conditions for detection. It was also successfully employed for screening of germplasm for virus resistance, detection of pathogens in vector insects, plantlets grown in vitro and in more sophisticated quantitative determinations of viral replication in artificially inoculated plants and protoplasts.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号